Possibly in fear that hackers will be able to find backdoors in the Intel Darwin version and allow OSX to run on PCs other than Macs, Apple has only posted the sources of Darwin for PPC for the latest version.

Nailed that one, 'Open', would appear to be just another buzz word to be bandied about as it suits Apple. It was pretty obvious when I went looking for a quicktime producer for linux or any other os, I recall the only thing open quicktime on linux seemed to be good for was serving up the mov's made on your mac in an expensive closed app. The open source community would be ahead of the game if it just completely ostracized them.